Indicator light with adjustable shutter



Qct. 12, 1954 V. A. MARCO INDICATOR LIGHT WITH ADJUSTABLE SHUTTER Filed 00*.

6 A AM 2/ 25 z r ,7 MA I 2 a A I g 52 Z 6 1 I8 45 27 :QQQQ 1 INVENTOR. ENT A MAR ATTORNEY- Patented Oct. 12, 1954 INDICATOR LIGHT WITH ADJUSTABLE SHUTTER Vincent Anthony Marco, Beverly Hills, Calif., as-

signor to Marco Industries Company, Anaheim, Calif., a corporation of California Application October 5, 1951, Serial No. 249,885

10 Claims. 1

This invention relates to indicator lights of the type commonly employed on instrument panels of aeroplanes, automobiles, and other machines, for indicating the condition of operation of various components of the machine. The invention relates particularly to the type of indicator light with adjustable dimming iris or shutter such as that embodied in the invention of F. J. Aves, covered by U. S. Patent No. 2,424,575, issued July 29, 1947. The present invention is an improvement upon the indicator light shown in that patent. In this type of indicator light, the housing, immediately below the lens, is provided with a plurality of iris members adapted to be moved toward each other to reduce the light emitting aperture, and to be closed together to completely shut off direct light emission. The advantage of such an arrangement arises from the varying requirements for light emission under daylight conditions (when relatively high intensity emission is desired) and conditions of darkness when it may be essential that the eyes of the pilot or operator be adjusted for maximum pupil dilation, in which case the amount of light emitted from the indicator light must be greatly reduced below the daylight requirements.

Indicator lights of this general type are commonly installed in many dilferent positions, some of which may place them so as to present substantially a complete side elevation to the operator, a position in which it may be impossible for the operator to view any illumination whatever in the lens of the device, especially in the dimmed condition thereof. With this problem in mind, the primary object of the present invention is to provide an indicator light of the type under consideration, which is capable of providing light emission throughout a complete 180 range about a center located at the indicator light and in a plane intersecting the longitudinal axis thereof, whereby the operator may see the glow of the indicator light from a viewpoint ranging anywhere from a head-on viewpoint directly in front of the light, around to a view point looking directly at any side of the light, and with the face of the lens completely out off from the operators line of vision.

A further object of the invention is to provide such an indicator light which will afford such complete range of light emission not only in the wide open position of the iris but also in the fully stopped down or closed position of the iris.

A still further object is to provide such an indicator light in which the intensity of both front and lateral light ray emission will be dimmed down proportionately throughout the entire aforesaid complete range of light emission in all directions.

Another object is to provide such an indicator light having improved heat dispersal qualities, and thereby adapted to operate at lower temperatures than the prior art indicator lights of this general class.

A further object is to provide such an indicator light which in addition to its improved characteristics indicated above, is of relatively simple, inexpensive and yet durable construction, lending itself readily to manufacturing operations so that it may be produced and sold in quantity at a reasonable price.

A further object of the invention, in a modified form thereof, is to provide an indicator light conforming generally to the characteristics outlined above but adapted in the open position to emit the light throughout its entire wide angle range, but in the closed position to emit light only from the front face of the lens.

With the foregoing objects in view, the invention contemplates, in general, an indicator lens and iris assembly in a cap for a light mounting housing, in which cap there is provided a mounting ring for attachment to the housing, said mounting ring having a basic light emitting aperture, a lens in front of said aperture, and a plurality of shutter or iris elements interposed between the lens and the mounting ring, together with a shell enclosing the mounting ring and securing the lens in assembly, said shell having, an addition to a front window through which the forward face of the lens projects, a plurality of side apertures for emitting light in a direction at right angles to the longitudinal axis of the assembly, said side apertures registering with the rim of the lens, and the iris elements being so arranged relative to the mounting ring as te provide for an emission of light rays not only from the front face of the lens but also through the rim of the lens and through said lateral light emitting apertures.

Other objects will become apparent in the ensuing specifications and appended drawings in which:

Fig. l is a front view of an indicator light assembly embodying the invention, with parts broken away to better illustrate the construction;

Fig. 2 is an axial sectional view of the same taken on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional View of an As an example of one form in which'the inven- A tion may be embodied I have shown in Figs. 1, 2 and 3 a portion of an indicator light assembly including a housing or barrel I adapted 'tohouse a signal lamp bulb I I having a filament 12."

The forward end of barrel I9 =isrexterna-lly:thread-. ed to be received in the internal thread I3 of a mounting ring I4 which has a face 'fia-nge I5 projecting radially inwardly from its outer extremity. Flange "I 5 :has an :inner edge -defining a ;light emitting aperture I6 :and providing ::an abutment against which 'therforward end :ofr-lamp bulb II is seated under yielding pressurewprovidedby resilient means which, since zit isrpart of' the. prior 'art'and forms no part of the present invention, is not disclosed herein.

Ring I 4 hasa cylindrical lateral wall I! which provides a bearing surface for a retainer shell t8,

:rotatablymounted thereon. Shell I8 has, at its rear end, an-integralinwardly turned fiange IIB which abuts, through interposed :bearing "washers ill-, against the rear end of mounting :ring- I4 410 .secure the shell .in rotatable assembly therewith. 'Atsits forward :end, shell-l8 hasan'zinwardly turned retainer flange 2 I, which providesan abutment foran offset shoulderin the rim of a lens 22. The above mentionedshoulder is definedas the forward face of an enlarged rim portion23. of lens-r22, the lenshavinga reduced forwardportion which snugly'fits within the windowwdefinedby the inner edge .ofzfiangeZ I. and projects forwardly from flange 2 I The rear;faceof lens 22 may be'concave as shown :or, alternatively, maybe flat. The .forward face ofi'the lensmay be-fiatorslight convex. The :periphery of enlarged rim portiontZB of the lens may be slightly frusto-conical as shown .or may be cylindrical, whichever ispreferred. The lens-may be constructedofrglass or other suitable transparent ortranslucent material although I .prefer :to employ alens molded .of aplastic material having ;a relatively high :index ofv refraction sogasztoz have what -is;.sometimes referred .to as diffusing-:characteristics (the --ability to trap ,a large percentage ofilight rays 'whichzenter the lens body at. an angle, and to transmit them out. to the edges of-zthe lens where'they will be emitted from the rim surface of the. lens with a scattering or diffusionyof the .lightrays). For example, the thermoplastic acrylic polymer resin commonly known under the trade-mark Plexiglas, ha-sthe mentioned .light diffusion qualities,-although.it-is tobe understood that it. is possibleztoremploy other transparent or translucent materials.

-In the lateral Wall of-shell' l8 are a plurality of light aperturesfl25, arranged immediately behind the retainer flange 2|, and registering with'the periphery zofenlarged rim portionu23 of lens '22, thus toallow the escape of lightrays emitted from saidrimportion.

Defined between the periphery of rim portion 23 and :theinner wall :of-shell I8 is an-annular space 21 in which air may .circulatefreely for. absorbing heatlradiatedfrom the-rim of the lens. The-air lamps.

the other.

in this space is in communication with external atmosphere through apertures 25, and it will thus be apparent that convectional circulation may take place, with air entering the lower apertures, passing upwardly around both sides of the lens through annular spac 2'? and escaping through the upperapertures 25;00- produce a cooling effect whichsisisuch that my'improved indicator lamp will operate at a lower temperature than prior The heat dispersal is improved by the conduction of heat from the interior of the cap to the annular space 2'! through an annular iris operatin and lens mounting ring 28 which will now'bedescribed.

Ring 28 :has :aperiphery fitted snugly to the inner :wall .offshell I8 and is therefore rotatable with shell It... Its forward face provides a seat for the rear face of lens 22, the rim portion 23 thereof being confined between ring 28 and retainer 2 I. The rear face of rin 28 is spaced from the forward face of facefiange I5 of .themountin ring It, so as to provide anarrow flat spacein whichi-sreceiveda pair of.shutter Or iris elements .29. his elements .29 have straight inner .edge

flanges 30 adapted to come together in overlapping relation along a-diameter of the cap assembly, and have semicircular outen margins. 3!, whereby when the .edgestil are overlapped .as indicated, the. two .iliS elements will cooperatively define a circular disc of somewhat larger diameter "than the basic light aperture I6, so as to completely shut oifthe emission of direct rays from "filament I2- Each .ofthe iris elements. 29 has at one end a radially extending arm 32 terminating ina forwardly bent finger 3.; received in aperipheral, radially extending notch 34 in operating ring Each iris element has at its other end a radially extending arm 35 provided with a rearwardly bent lug 36 which is pivoted in a socket 3'! inface flange l5 of'mounting ring M. The arm 32 of one iris member is diametrically opposed to arm 32 of The same is true of arms -35. It will now be apparent that, upon rotation of shell I8 in a counter-clockwise direction as viewed in Fig. l, the iris elements 29 will be separated radially to provide'a parallel sided opening in front of aperture "I6, through'whichdirect rays from filament I2 may be emitted forwardly through lens 22. The size of this openin between iris elements '29 may be adjusted to any desired'width bythe degree of rotation of shell I I 8, 'froma-point where only a thin, diametral light'space is defined between adjacent flanges '30, to a point where most ofaperture- I 6 is'uncovered.

Overlapping flanges 3i! are'adapted to completely seal the iris members together against any possible escape of light. rays between them, in the fully closed iris positions.

The .inner portion of face flange I5 has a bevelled;fr.usto-conical,' forward face 39 which'intersectsithe fiat forward face of flange I15 to define .a circular edge Ml. Between frusto-conica1 face 39 and the semi-circular outer edges .3I of iris elementszfi, there is defined a pair of arcuate, op.- posed'light passages ll. Light passages ll terminate at the'arms 32 and .35 of iris elements .29..

Operatin ring 28,.as previously stated, has a circular rim which is snugly fitted within shell I8. Its inner periphery is roughly in the shape of .a figure 8, whereby the ring includes two diametrically opposed wide portions 42, accommodating slots, and tworelatively narrow portions 43,-,the inner 'margins of which are disposed along arcs eitherregistering with or having a diameter greater than the diameter oftheinner-margin of retainerflan e #ZI. Theopening thustdefinedby the inner margin of ring 28, has a.pair:of diametrically opposedportions which,'spaced radially outwardly from aedges3l ofv shutter element 29, cooperate therewith to define crescent shaped openings 45 in the closedpositions of iris elements 29 'shownin Fig. l. The openings, lying immediately forwardly of light passages4l,-provide for full visibility of the latter throughthe lens 22.

Itmay now be noted that,,in the closed position of the, iris element, 29 shown in the. drawings, a pairof semi-conical bands 46 oflight rays from filament 12 will escape through the opposed arouate passages 4I-into openings45. These rays, reflected in various directions from the inner surfaces of ring 28 iris elements, 29, and lens 22, will include many rays falling upon. frusto-conical face 39 of flange l5 and illuminating that portion thereof which is visible through passages 41. Thus, in the fully closed. iris position, there will be-visible two arcuate bands 41 of light rays cor-- responding to the shapes of passages 4| as viewed from the front (Fig. 1) through lens 22.

These rays are diffused through a wide angle as indicated, whereby the illumination may be seen from any directionin front'oflens 22, at any angle of incidence down-to an angleless than 45.

. Rays 46 striking lens 22 from passages will be sufficiently spread out to include rays which enter the lens at such an angle as to borefracted out to the rim portion23 thereof,-from which they wi l be emitted, as indicated at. 48,v in the form of a series of generallyradial rays or spokes of light, each of conical formand spreading sufficiently tointersect the rear extremity of the annular band of diffused. rays 41 emitted from the forward face oflens 22.

The lateral light. rays 48, in the fully closed positions of iris members. 29, are derived solely from the indirect rays46 passing through arcuate passages 4|. However, as the iris elements 29- are gradually separated, bands of direct rays passing directly between the iris members will strike lens 22 and these rays will spread out sufficiently so that some of the outer rays will be refracted out through the rim 23 of the lens fromwhich they will be emitted-to form therays, 48 of greater intensity than those emitted in the fully closed position of the iris. The intensity of rays48 will increase in step with the intensity of the direct beam of light passing forwardly between the iris members and through lens 22. Thus, the visibility of the lateral rays48will vary in direct proportion tov the visibility of the forward rays 4'! emitted from the face of lens 22.

Because the forward rays and the lateral rays 48 are in. intersecting relation, the visibility of the glow emitted from the indicator light will be continuous throughout the entire range of vision from aviewpoint directly at any side of the shell I8 around. to aviewpoint directly along the axis of lens 22 from the front There will be no blind spot in this range of vision. Accordingly, it is entirely immaterial in what position the indicator light isinstalled. It may be viewed by the operator in any position of possible vision from front or sides, and the intensity of the emitted glow will be dimmed proportionately both at the front and at the sides, as shell I8 is rotated from a full open to a full closed position of the iris member.

In the modified forms of the invention'shown in Figs. 3-5, the construction is the same as in Figs. 1, 2 with the exceptions noted: Fig. 3 shows how light apertures 26 instead of being open, may

be filled with smallnjewels 50 which may be of the same material as lens 22. or of" any: other light transmittingmaterial. Jewels-50 are preferably provided with faceted faces 5| for emittingrays of lightin' all directions.

Fig. 4 discloses how, if desired, the, jewel elements 5| may be formed integrally with an enlarged rim portion 23' of the lens 22, the entire lens and jewel body being integrally molded. into shell l8.

Fig. 5 illustrates how. shell. l8" may havelight apertures 26' which are considerably elongated in a circumferential direction and separated by thin axially extending web members'52. bridging between the bodyof shell. 18 and the retainer flange member 21 thereof.

Fig. 6 illustrateshow the parts may be arranged so as to obtain only front emission in the closed position of the .iris, with lateral emission cut off, whereas in all open positions of the iris there will be lateral emission aswell as front emission, the same as in the other forms of the invention. Inthis modification, the. narrower portions 43 of ring. 28' are wider than the portions 43 of Figs. 1-5, thereby cutting off the outer portions of light beams 46 where they-pass through openings 45, to anextentsuoh that none of the rays strike .lens 22 at a sufficiently spreading angle to be refracted outwardly to. the rim 23 of thelens. Light rays passing to the lens through the central aperture between the iris segments 29 in any position of substantial .opening thereof will, however, include. some rays which will be'refracted outwardly to the lens rim.

It may now be noted that in the preferred arrangement of Fig. 2, the .portions43 ofring 28 are sufiiciently. narrow so that the. radially outer limits of light openings 45 are positioned so as to allow asubstantial quantity of light rays to enter lens 22: at a sufficiently spreading. angle to effect outward refraction to the rim 23, from which theserays will'be diffused through openings .28 as. previously pointed out.

I claim:

1.. In a lens holder'and iris cap. for an indicator light having a barrel adapted to house a lamp bulb inits outer end: a mounting ring attachable to saidouter end and having aradially inwardly projecting. faceflange defining aprimary light emission aperture associated closelywith the tip of said lamp; a retainer shellhaving a cylindrical lateral-- wall portion receiving and rotatab y mounted .onsaid mounting ring, said shell having at its forward. end aradially inwardly extending retainerflange defining a forward light emitting window and havingin said. lateral wall portion, adjacent said retainer flange, a plurality of lateral light; emitting apertures; a lens mounted in said window and having a rim portion retained behind saidretainer flange and adapted to emit diifused define a central opening for passage of direct I rays forwardly from said lamp; said face flange having a forward face spaced axially from the periphery of said iris in the closed position thereof to define a pair of arcuate passages for the emission of indirect light rays in a pair of semi-conical beams passing forwardly from said lamp to said lens and adapted to emit minimum illumination from both the periphery and face of said lens.

2. A lens holder as defined in claim 1, wherein the periphery of said lens is spaced radially inwardly from the inner wall of said lateral wall portion of the shell to define an annular space in which air may circulate by convection in and out of said lateral apertures and around the peripheryof the lens to cool the same.

3. A lens holder as defined in claim 1, including a plurality of small lens mounted in respective lateral apertures for increasing the diffusion of light rays passing therethrough.

4. A lens holder as defined in claim 1, wherein said lens has an integral rim extending radially outwardly to said lateral apertures and having small lens projections integral therewith and extending through respective apertures.

5. A lens holder as defined in claim 1, wherein said lateral apertures are in the form of circumferentially elongated slots separated by narrow web portions of said lateral wall portion.

6. In a lens holder and iris cap for an indicator light having a barrel adapted to house a lamp bulb in its outer end: a mounting ring attachable to said outer end and having a radially. inwardly projecting face flange defininga pri-' ward light emitting window and having in said lateral wall portion, adjacent said retainer flange, a plurality of lateral light emitting apertures; a lens mounted in said window and having a rim portion retained behind said retainer flange and adapted to emit diffused light rays from its" periphery through said lateral apertures; an operating ring mounted within said shell immediately behind said lens and rotatable with said shell; a pair of iris segments disposed between said face flange and said operating ring and adapted to come together along a diametral joining line to collectively define a cover for said primary aperture to out 01f direct light rays from said lamp; connections between said operating ring and said segments for moving them, upon rotation of said shell, between their adjoining positions and separated positions in which they define a central opening for passage of direct rays forwardly from said lamp; said face flange having in its forward side a recessed frusto-conical face adjacent said primary aperture and spaced from the periphery of said iris in the closed position thereof to define a pair of arcuate passages for the emission of indirect light rays in a pair of semi-conical beams passing forwardly and radially outwardly from said lamp to said lens and adapted to emit minimum illumination from both the periphery and face of said lens.

7. In an indicator light having a housing and a lamp bulb therein: a lens holder including a shell rotatable on said housing, said shell having a retainer flange defining a front window and having a side wall provided with a plurality of apertures adjacent said flange; a lens having a rim portion retained behind said flange and lying in the common plane of and with the edge of said rim communicating with said apertures; means to intercept and block substantially all direct rays from said lamp bulb to said apertures; and means adapted upon rotation of said shell, to define a central light opening for the passage of light rays from said lamp to said lens, said lens being adapted to transmit some of said rays forwardly through said window and to transmit othersof said'rays laterally to said rim, and to diffuse said laterally transmitted rays from said rim through said apertures.

8. An indicator light as defined in claim 7, including annular means interposed between said iris means and said lamp bulb, defining a primary light opening which, in the fully closed position of the iris means, provides a narrow arcuate light passage at the periphery of the iris means, for transmitting a minimum quantity of light rays to said lens.

9. In an indicator light having a housing and a lamp bulb therein; a lens holder including a shell rotatable about said housing, said shell having a retainer flange defining a front window and having a side wall provided with a plurality of aper tures adjacent said fiange; a lens having a rim portion retained behind said flange and registering with said apertures; iris means adapted, upon rotation of said shell, to define a central light sage at the periphery of the iris means, for transmitting a minimum quantity of light rays to said lens; and a ring disposed immediately ahead of said iris means and defining a light opening of sufiicient radius to allow some of said minimum light rays to spread laterally sufiiciently to reach said lens rim and be diffused through said lateral apertures.

10. An indicator light as defined in claim 9, wherein said light opening is of such restricted radius and said ring is so positioned as to intercept the lateral portions of said minimum light rays proceeding in a direct path toward said apertures, while transmitting inner portions of said minimum rays into said lens adjacent said rim for said diffusion.

References Cited in the file of this patent UNITED STATES PATENTS 

